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In this paper, an investigation of changes in pH of capacitance in EIS is proposed. This way could be easily implemented by the discrete integrated circuits in the ready-made market. Capacitive variations can be detected and converted into voltage changes by signal conditioning. All the functions of the system are proved successfully through HSPICE simulation. These simulation results have successfully confirmed the correct functions and good performance in linearity. [ABSTRACT FROM PUBLISHER]

This paper presents the development of the virtual pH analyzer that can be used for continuous process applications. The development of virtual pH analyzer is divided into two parts: virtual pH measurement and virtual pH control system. The G-programming language potentialities of LabVIEWTM version 2011 running on a Dell Core 2 Duo 2.0GHz, 3GB RAM computer with Windows 7 Ultimate operating system was utilized for data acquisition and control. The pH measurement phase consists of two components namely data acquisition and data display whereas the pH control system phase comprises of data processing and control signal generation components. The front panel has been designed to mimic the actual pH analyzer and the ON/OFF control strategy is applied for pH control system. The accuracy of the developed virtual pH analyzer is tested by comparing the reading from the conventional instrument. The results had shown the improvement in term of the accuracy and flexibility as compared to the conventional pH instruments. [ABSTRACT FROM PUBLISHER]

We have constructed a simple estimation method of the dependence to photosynthetic rate of the light intensity using semiconductor pH sensor. As the rearing environment is important for effective growth of plants, simple measurement method of the photosynthetic rate is desired. Plants in photosynthesis absorb carbon dioxide (CO2) and release carbohydrates and oxygen. As CO2 is readily soluble in water and decrease pH, the pH of water reflects the degree of photosynthesis of water plants. To quantify the small changes of pH, we applied an automated pH measurement system consisting of ion-sensitive field effect transistor (ISFET) sensor we developed earlier. The pH measured in a test tank (0.35 L) containing a small quantity (2 g) of water plant Egeria densa rose by 0.15 (100), 0.5 (500), 1.0 (1000), and 1.7 (2000) (Differential pH (Lux)) after 5 hours light irradiation. [ABSTRACT FROM PUBLISHER]